Re: Safety gap electrodes

["Barton B. Anderson" <tesla123-at-xxxxxxxxxxx> (by way of Terry Fritz <twftesla-at-xxxxxxxxxx>)]

Hi Gary, Ed, 

Just wanted to reinfornce Gary's comments here. I found the exact same problem
using very heavy solid copper wire (looped) for a safety gap. The arc jumps at
the smallest ROC which is the wire diameter and not the loop. Later replaced
safety gap with a 1 inch solid copper spheres. Problem gone. 

Bart 

Tesla list wrote: 
>
> Original poster: "Lau, Gary" <Gary.Lau-at-compaq-dot-com> 
>
> Wire electrodes are not well suited for safety gaps.  I tried using heavy 
> wire electrodes as you described in parallel with my cap and was appalled to 
> see it arcing at over 3/4" spacing!  How could this be, given that my main 
> static gap had less than 3/8" gap?  After all, the cap voltage can be no 
> higher than the main gap voltage. 
>
> I replaced the wire loop electrodes with spoon faces, to give a very large 
> radius of curvature.  Presto - the arcing distance went down to about 3/8", 
> same as my main gap. 
>
> Moral of the story is, heavy wires have a very small radius of curvature 
> defined by the wire diameter, not the loop diameter, and this small ROC will 
> promote corona and premature gap breakdown. 
>
> I recommend brass drawer knobs for safety gap electrodes. 
>
> Regards, Gary Lau 
> Waltham, MA USA 
>
> -----Original Message----- 
> From: Tesla list [<mailto:tesla-at-pupman-dot-com>mailto:tesla-at-pupman-dot-com] 
> Sent: Tuesday, October 31, 2000 6:44 PM 
> To: tesla-at-pupman-dot-com 
> Subject: Safety gap electrodes 
>
> Original poster: Esondrmn-at-aol-dot-com 
>
> I am working on a new sync rotary gap and want to install a new safety gap 
> across the rotary.  I plan on setting the gap to approximately .450".  I 
> have 
> used # 10 copper wire for this in the past with 1.0" dia. loops on each end. 
>
> I would like to use 1.0" to 2.0" round copper or brass electrodes for the 
> new 
> safety gap.  Does anyone know where I can get these?  Hopefully somewhere 
> that does not require a $25.00 minimum order. 
>
> Thanks, Ed Sonderman